Unit 4

• Consciousness


  Our moment-to-moment awareness of our self and our environment
• Aspects of consciousness


  • The extent to which we are aware of our thoughts, feelings, aroused states, and our surroundings
  • Different levels of consciousness
• Functions of sleep


  • Restoration of body tissue and promoting growth
  • Helping increase our immune functioning
  • Keeping the mind alert
  • Enhancing mood
  • Promoting advances in cognition, learning, and memory

  
• Factors influencing amount of sleep needed

  • Age
  • Lifestyle (environment)
  • Genetics: night owl or morning lark?
• Circadian rhythm


  Schedule that body follows naturally for basic functions like sleep, waking, and eating
• Suprachiasmatic nucleus (SCN)


  Part of the hypothalamus that acts as the body's internal alarm clock
• Amount of light around us


  Affects how SCN triggers release of melatonin
• Without natural light people's natural cycles run a bit longer than 24-25 hours
• Light is needed to "re-set" the circadian clock each day
• Stages of sleep


  • Waking
  • Stage 1
  • Stage 2
  • Stages 3-4
  • REM

  
• Beta waves


  Observed in people who are awake and alert, reflecting active brain handling sensory processing and active, conscious thinking

  
• Alpha waves


  Observed in people who are awake, but relaxed and perhaps a bit drowsy or understimulated, reflecting a decrease in stimulation and associated brain activity
• Theta waves


  Observed in Stage 1 sleep, where muscles relax and the person is less responsive to stimuli in the environment

  
• 1. complexes and sleep spindles

  Observed in Stage 2 sleep, where slow, regular theta waves are interrupted, reflecting the brain's attempt to monitor the environment while still allowing one to fall asleep

  
• Delta waves


  Observed in Stages 3-4 of sleep, where muscles are fully relaxed, heart rate slows dramatically, and the person is mostly unresponsive to their surroundings
• REM sleep


  A mix of sleep and waking, where the brain activity is similar to being wide awake (beta waves), dreaming occurs, eyes move back and forth, and major muscles are paralyzed

  
• REM sleep is especially important for brain development and memory consolidation

  
• REM rebound occurs when people lose REM sleep and then make up for it by spending more time in REM sleep on subsequent nights
• Freud's wish fulfillment theory of dreams


  Dreams help us explore urges or resolve conflicts in a safe, no-consequence setting
• Continuity hypothesis of dreams


  Dreams help us deal with the daily problems and issues of life
• Memory theory of dreams

  Dreams help consolidate memories from our waking hours

  
• Activation synthesis model of dreams

  Dreams have no deeply held symbolic meaning, but are just a by-product of electrical activity in the brain while we sleep

  
• Threat simulation theory of dreams


  Dreams let us practice our responses to dangerous situations in a risk-free environment
• Sleep disorders


  • Insomnia
  • Narcolepsy and cataplexy
  • Sleep apnea
  • Night terrors
  • Restless leg syndrome
  • Sleepwalking
  • Enuresis (bedwetting)

  
• Insomnia


  Unable to get the sleep you need, despite trying to do so, including both onset insomnia (trouble falling asleep) and maintenance insomnia (trouble staying asleep)

  
• Narcolepsy


  People suddenly go to REM sleep directly from wakefulness
• Cataplexy


  Muscle paralysis that accompanies REM sleep, occurring suddenly while the person is still fully alert
• Sleep apnea


  Breathing can stop for a minute or more before the body's alarms wake the sleeper, often caused by being overweight and/or heavy snoring
• Night terrors


  Intense fear and distressed behaviour without dream content, occurring during the transition from Stage 4 sleep to REM sleep

  
• Restless leg syndrome (RLS)


  Neurological movement disorder occurring primarily at night, with unpleasant sensations in the legs and an irresistible urge to move them

  
• Periodic limb movement (PLMS)


  Involuntary leg twitches or jerking movements, occurring roughly every 15 to 40 seconds, sometimes throughout the night

  
• Sleepwalking (somnambulism)


  Occurs during non-REM slow-wave sleep, where the sleeper gets up and walks around during deep sleep
• Enuresis (bedwetting)


  Diagnosed when a child who is at least 5 years old wets their bed or pajamas at least twice a week over a 3-month period
• Hypnosis


  A state of heightened suggestibility and relaxation, where the person is willing to follow instructions

  
• Neodissociation theory of hypnosis

  There are two states occurring at the same time: the "self" in the hypnotic state, and a hidden observer who can see everything that is going on

  
• Response set theory of hypnosis

  We are not really in an altered state, but rather are behaving in the way we think we should when hypnotized - acting out a role

  
• Meditation


  Techniques to enhance positive emotions by letting go of conscious thought, such as focusing on breathing, specific objects, sounds, or feelings of love and kindness
• Mindfulness


  A form of meditation that involves being focused and aware of the present moment
• EEG recordings suggest meditation produces a state like relaxed wakefulness, with increased alpha-wave activity
• Psychoactive drugs


  Substances that influence the brain and thereby a person's behaviours